Movement to smaller design rules for semiconductor devices has been accelerated year by year in order to increase the integration degree and the operation speed of ULSIs (ultra large scale integration) or the like used in computers. Accordingly, there are an increased number of cases where nanoscale fine surface defects on a substrates used in a semiconductor device adversely affect the performance of the semiconductor device. Therefore, it has been increasingly of importance to control fine surface defects that have never been regarded as a problem.
Some fine surface defects occurring on a substrate result from foreign matter, such as polishing materials (e.g., abrasive grains), additives (e.g., water-soluble polymer), polishing pad debris, swarf generated from the substrate by polishing, or dust in air, that have been adsorbed on the substrate surface and failed to be removed in a cleaning step to remain on the substrate.
In order to reduce such surface defects due to foreign matter, it is effective to impart hydrophilicity to a substrate surface after polishing, thereby enhancing removal efficiency of foreign matter in a cleaning step. Patent Document 1, for example, discloses that a water-soluble polymer of which viscosity has been adjusted is used in a polishing composition for the purpose of imparting hydrophilicity to a substrate surface after polishing.